18871434156385 has 4 divisors (see below), whose sum is σ = 22645720987668. Its totient is φ = 15097147325104.

The previous prime is 18871434156343. The next prime is 18871434156469. The reversal of 18871434156385 is 58365143417881.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9690825034081 + 9180609122304 = 3113009^2 + 3029952^2 .

It is a cyclic number.

It is not a de Polignac number, because 18871434156385 - 2¹⁵ = 18871434123617 is a prime.

It is a super-2 number, since 2×18871434156385² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1887143415634 + ... + 1887143415643.

It is an arithmetic number, because the mean of its divisors is an integer number (5661430246917).

Almost surely, 2^{18871434156385} is an apocalyptic number.

It is an amenable number.

18871434156385 is a deficient number, since it is larger than the sum of its proper divisors (3774286831283).

18871434156385 is an equidigital number, since it uses as much as digits as its factorization.

18871434156385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3774286831282.

The product of its digits is 77414400, while the sum is 64.

The spelling of 18871434156385 in words is "eighteen trillion, eight hundred seventy-one billion, four hundred thirty-four million, one hundred fifty-six thousand, three hundred eighty-five".